Diseases & National Health Programme
Most common site of hydatid cyst is:
a. Hydatid disease is a 'zoonosis' and infective larva of the canine intestinal tapeworm Echinococcus causes the disease in man.
b. Human infection occurs by ingestion of the eggs of Echinococcus inadvertently with food, unwashed vegetables or water contaminated with feces from infected dogs.
c. Infection can also take place by handling or playing with infected dogs (hand to mouth transfer of eggs, or by inhalation of dust contaminated with infected eggs).
d. The disease is not directly transmitted from person to person. Disease is maintained in the 'dog-sheep' cycle.
e. Other combinations may also be involved such as 'dog-goat', 'dog-cattle', and 'dog-camel'. Eating viscera containing hydatid cyst infects carnivores.
f. The adult tapeworm lives in the small intestine of dogs (definitive host) for 2 to 4 years.
g. Slowly enlarging echinococcal cysts generally remain asymptomatic until their expanding size or their space-occupying effect in an involved organ elicits symptoms.
h. The liver and the lungs are the most common sites of these cysts. More than 70% of the cysts become located in the right lobe of the liver, and the rest in lungs, brain, peritoneum, long bones, and kidney.